It is known to generate images of a patient's teeth in order to determine their state of health as well as to diagnose and treat diseases. Further, for the treatment of diseases or injuries that affect the root tip or nerve of the tooth, an image or other presentation of the periapical area of the teeth is most desirable. As used herein, “an image or other presentation of the periapical area of the teeth” means an image or other presentation that shows the whole tooth both above and below the gum line. Such images and presentations include radiographs recorded on X-ray film and images provided by a digital image sensor.
Digital images are captured by either digital imaging plates located within the patient's mouth or a digital imaging sensor that provides a signal via a cable or wireless transmission to a computer that generates a visual display of the periapical area of the teeth. Generally, X-ray films and imaging plates are of standard sizes and therefore, are subject to being supported by a holder of a fixed size, which can be accommodated in the patient's mouth with reasonable comfort. In contrast, digital sensors do not have standard dimensions and are often relatively large and bulky and are often connected to an electrical cable; and thus, the handling of digital sensors in the patient's mouth is somewhat problematic and often uncomfortable for the patient. As used herein “mouth” means an oral cavity containing the tongue and teeth between the lips and the pharynx.
Imaging mediums including digital sensors are commercially available in different sizes that produce different image formats. It is known to provide different size holders to accommodate different size imaging mediums and digital sensors. There are also known holders that can accommodate digital imaging sensors of different sizes; however, commercially available holders have several disadvantages.
Commercially available holders locate and clamp a sensor with respect to a locating surface adjacent to a bite plate that is clenched between the patient's teeth. By locating and securing the sensor adjacent to the bite plate, the apical area of the tooth is often outside the field of vision of the sensor and thus, not included in the image. As used herein, the “apical area” refers to the portion of the tooth around the root area of the tooth. The absence of apical area in the image requires further imaging by reorienting the sensor or using a larger sensor. In either event, valuable time in the dental suite is lost with a further penalty of additional patient discomfort and irritation. Therefore, there is a need for a sensor holder that accurately, reliably and repeatedly locates and secures sensors of different sizes in the oral cavity, so that the apical area is included in the image or presentation and a complete presentation of the periapical area of the teeth is obtained.
Sensor clamps have either a passive structure that have no moving parts and clamping is accomplished by opposed resilient clamp arms or, an active structure in which a clamping action is obtained by one or more parts being movable with respect to other parts. With such active structures, a movable part is often layered on a static part or a movable part is partially or wholly enclosed by a static part. In either event, the sensor clamp has a bulk and thickness that is often greater than sensor clamps of a passive structure. Further, portions of the sensor clamp often overlay an imaging field of the sensor, and those sensor clamp portions can appear as artifacts or shadows in the resulting image. Further, with active structures, additional artifacts or shadows can be caused by movable parts of active structures that present different thicknesses in the imaging field. Therefore, there is a need for a sensor holder of an active structure that substantially reduces and minimizes artifacts and shadows in a resulting image.
Known sensor holders often have a movable part partially or wholly enclosed within a static part, thereby forming enclosed volumes within the sensor clamp structure. Such enclosed volumes present barriers to the flow of steam or other sterilizing fluid and are difficult to completely sterilize between uses. Therefore, there is a need for a sensor clamp having an active structure that can be easily and reliably sterilized between uses.
Commercially available sensor holders capture the sensor between movable arms or pads that can be locked in place. However, if the sensor is not carefully located and tightly secured between the arms, the sensor may experience motion, which often adversely affects the quality of the presentation of the resultant image. Therefore, there is a need for a sensor holder in which the sensor is more securely mounted and secured.